The invention relates to a magnet assembly for the suspension and guidance of vehicles and transport systems. The magnet assembly can be used particularly for those vehicles and transport systems, which are constructed for locomotion along a magnetic rail without contacting the latter and, with that, make possible a frictionless and wear-free locomotion.
In principle, two magnets cannot assume a stable position relative to one another without contact or support. Any magnetic transporter system, which is based on magnetic levitation, therefore requires a mechanical support or a control of the magnetic fields. If magnetic guidance for a stable, suspended state is to be realized with these elements, additional guiding magnets are required aside from the supporting magnets.
A stable, contactless magnetic suspension is, however, possible with superconductors in suitably shaped magnetic fields since, contrary to all other materials, a superconductor either does not penetrate into the magnetic field or, once such a magnetic field is present in its interior, maintains it unchanged. This is due to the fact that the magnetic flux penetrates into a superconductor in the form of flux lines, which can be anchored at defects in the material. Accordingly, if a superconductor, which contains many so-called pinning centers, is cooled in an inhomogeneous magnetic field to a temperature below its superconducting transition temperature, the form of this external magnetic field can be “frozen” in the respective position in the superconductor. If an attempt is now made to bring the superconductor out of this position, then this attempt is counteracted by a restoring force, which may be very large. For example, if the superconductor is made superconducting in a position, which is fixed by means of a spacer a few millimeters or centimeters above a magnetic rail, the superconductor retains this position, even after the spacer is removed, without contacting the rail. In other words, the superconductor has a repelling as well as an attracting effect in the magnetic field. If the magnetic rail has a uniform magnetic field along its length, the superconductor can move along the rail without contact and, with that, also without friction and without wear.
With the help of this principle, the possibility has already been demonstrated of the contactless transport in a state suspended above a magnetic rail, but also along a wall, which is equipped with a magnetic rail, as well as freely suspended below a magnetic rail. The disadvantage of such an assembly lies therein that the superconductor requires cooling. In the event that the cooling fails, such a suspended transporting system would crash in the absence of additional safeguards.